[WinEH] Adjust decision to emit SEH moves for leaf functions

[WinEH] Adjust decision to emit SEH moves for leaf functions

Move the check for "MF->hasWinCFI()" up into the calculation of the
shouldEmitMoves boolean, rather than putting it in the early returning
if. This ensures that endFunction doesn't try to emit .seh_* directives
for leaf functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298276 91177308-0d34-0410-b5e6-96231b3b80d8